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PHOTOSYNTHESIS AND CELLULAR RESPIRATION. By: Diana Boyle, Jordan Capelle , Ross Dairiki, and Erika Keer. Basic Info. Definition : process of using sunlight (light energy) to turn carbon dioxide & water into glucose (chemical energy) & oxygen Equation : 6 CO2 + 6 H2O --> C6H12O6 + 6 CO2 - PowerPoint PPT Presentation


  • PHOTOSYNTHESISANDCELLULAR RESPIRATIONBy: Diana Boyle, Jordan Capelle, Ross Dairiki, and Erika Keer

  • Basic Info.Definition: process of using sunlight (light energy) to turn carbon dioxide & water into glucose (chemical energy) & oxygenEquation: 6CO2 + 6H2O --> C6H12O6 + 6CO2Location: chloroplast of cell2 part process: Light-Dependent (Light) Reactions, Light-Independent (Dark) Reactions

  • Diagram of a Chloroplast:

  • Light-Dependent ReactionsAlso known as light reactionsDefinition: Uses energy from sunlight to split H2O and produces ATP (form of energy) & NADPH (electron carrier) as well as O2 (waste product)Location: thylakoid membrane of chloroplast- Membrane=studded with protein-complexes- Contains primary electron acceptor- Contains light-absorbing pigments - Primarily chlorophyll a and chlorophyll b- Accessory pigments (help plants use more light since each pigment absorbs specific wavelength)

    2 types:1) Linear Electron Flow 2) Cyclic Electron Flow

  • Linear Electron FlowPhotosystem II: Contains reaction center called p. 680 (absorbs 680 nm light best)Photosystem I: Contains reaction center called p. 700 (absorbs 700 nm light best)

  • Steps of Linear Electron Flow:1) Light hits antenna pigments of PSII, which passes energy to chlorophyll a, exciting some of its electrons; it gets replacement electrons from H20 molecules, leaving O2 and H+ ions in the lumen

    2) As energized e- pass along proteins in the membrane (called electron transport system/ETS), some of the electron transport energy is used to pump H+ ions into the lumen

    3) The e- go to PSI and replace electrons lost by p700 when it was hit by light

  • Steps of Linear Electron Flow (continued)4) The excited e- from PSI go along membrane proteins to NADP+, which then forms NADPH in the stroma, absorbing H+ ions

    5) The H+ pumped into the lumen (and H+ removed from stroma by NADP+) form a chemiosmotic gradient, which is used for synthesis of ATP as those H+ ions return to the stroma by way of a special protein in membrane ATP synthase

  • Cyclic Electron Flow1) Light energy energizes an electron from PSI

    2) e- travels through ETS proteins; this pumps H+ into the lumen3) e- returns to PSI; a chemiosmotic gradient is used to make ATP

  • Light-Independent(Dark) Reactions/Calvin CycleDefinition: The process of fixing CO2 into glucose using NADPH and ATP from the light-dependent reactions

  • Steps:1) 6 CO2 join with 6 RuBP (Ribulose Bisphosphate) with help of RuBisco enzyme (Ribulose Bisphosphate Carboxylase) to form unstable 6-carbon molecule

    2) 6 6-carbon molecules split into 12 13-PG (3-phosphogylcerate) molecules

    3) Energy and a phosphate from 12 ATP are added to the 3-GP forms 12 13-BPG (1, 3-BisphosphoGlycerate)

    4) 12 NADPH turn 12 1, 3-BPG into 12 G-3P (Glyceraldehyde 3-Phosphate)

    5) 2 of 12 G-3P become 6 RuP (Ribulose Phosphate)

    6) Energy and P from 6 ATP turn 6 RuP (Ribulose Phosphate) into 6 RuBP cycle begins again

  • The following music video includes some general information about photosynthesis to provide a break from slides! Sorry for the freeze frames, they were needed to sync timing.Enjoy!

  • C3, C4, and CAM plantsC3 plants: use CO2 to first make a 3 carbon molecule in the Calvin Cycle (normal photosynthesis plants)Photorespiration: RuBisco by mistake adds O2 instead of CO2 when conditions are hot, dry, brightTakes energy to remove O2 and return RuBP for use in Calvin CycleOccurs when [CO2] is low and [O2] is highC4 plants: 1st add CO2 to make a 4 carbon molecule Special structure: mesophyll cells do light reactions and C4 carbon fixationPEP carboxylase adds CO2 to PEP to make 4 carbon molecules4 carbon molecules go to bundle sheath cells. Bundle sheath cells (around vascular tissue)=specialized for doing Calvin Cycle. Remove CO2 from 4 carbon molecule so it can be used in the Calvin Cycle. ATP recycles PEP& returns it to mesophyll cellsCAM plants: absorb CO2 at night to make an acid, then break that down during the day to provide CO2 for the Calvin Cycle to make glucose (acid metabolism)

  • Cellular Respiration!Definition: Breakdown of molecules to gain energy (ATP), catabolismEquation: C6H12O6 + 6O2 6CO2 + 6H20 + Energy (ATP)Reverse of photosynthesis Location: mitochondria (aerobic)/cytoplasm (anaerobic & aerobic)

  • Type 1: Anaerobic RespirationDoes NOT require O2, occurs in cytoplasm & has two partsPart 1: Glycolysis: splits glucose to make pyruvate and gets some energy (ATP)Part 2: Fermentation: allows glycolysis to continue, recycles NADH back to NAD + (does not generate ATP)

  • Glycolysis(Occurs in the mitochondrial matrix)

    2 ATP added to glucose turns into fructose 1,6-bisphosphate, making it easier to split, cant diffuse from cell (energy SPENT)

    Fructose 1,6-bisphosphate splits forms 2 G3P molecules

    2 Phosphates & NAD+s come in; the NAD+ takes 2 electrons becomes NADH, while P is stuck on, turning each G3P into 1,3-bisphosphoglycerate (1,3-BPG)2 1,3-BPG lose 2 P to 2 ADP creates 2 ATP; 2 1,3-BPG become 2,3-phosphoglycerates (3-Pg)

  • FermentationPyruvate can become CO2, alcohol, lactic acid (humans do lactic acid fermentation when not enough O2 is present, as in heavy exercise)Net energy gain for anaerobic respiration (glycolysis & fermentation)=2 ATP/glucose

  • Type 2: Aerobic RespirationREQUIRES O2, occurs in cytoplasm then mitochondria. 3 parts:1) Glycolysis2) Citric Acid Cycle3) Electron Transport System

  • Steps of Citric Acid Cycle:Pyruvate loses a CO2 and NADH is formedCoenzyme A combines with C, forming Acetyl-CoA, which immediately combines with oxaloacetate, forming citric acid; Acetyl-CoA falls back off to be recycledCitric Acid turns into isocitrate, then NAD+ pulls off 2 electrons, turning into NADH; this makes Co2 fall off, forming alpha-ketoglutarate, turning into succinyl-CoA; NADH=formed as CO2 falls offCoA falls off, forming succinate; some energy from this=used to form GTP (transfers the energy to ATP)FAD takes 2 electrons from succinate, making FADH2; succinate becomes fumarate Fumarate becomes malate, which loses 2 electrons to NAD+ creating NADH and re-creating original oxaloacetate(Oxes Are Crazy In Kansas. So Should Foxes Marry Oxes?)

  • ETS/Chemiosmotic (oxidative) photophosphorylationUses electrons from NADH and FADH2 to create an H+ gradient for ATP synthesisLocation: cristae of mitochondria (folds in membrane)

    Steps:NADH and FADH2 drop off e- on the ETS e- pair from NADH have enough energy to pump 10 H+Electron pair from FADH2 have enough energy to pump 6 H+Electrons eventually end up on O2, forming H2OAbout every 4 H+ ions, as they go out the ATP synthase channel

  • ENERGYATP created by ETS:2 NADH (glycolysis) 3 ATP8 NADH (Krebs cycle) 20 ATP2 FADH2 (Krebs cycle) 3 ATP

    The net energy gain (for 2 pyruvates/1 glucose):1 ATP 2 ATP2 NADH 8 NADH1 FADH2 2 FADH2

    Energy gain (theoretical) from 1 glucose for aerobic respiration:

    Glycolysis 2 ATPKrebs Cycle 2 ATPETS 26 ATP

    TOTAL=30 ATP

  • BibliographyTextbook Website in general: CHAPTER 38- Parts of flower, fertilization, male/female gametophytes, hummingbird, double fertilization, seed structure, origin of fruits, and preventing self-fertilization CHAPTER 39- Reception and transduction and response, flowering hormone, and avirulent defense responses

  • Bibliography Cntd.(Linear electron flow)- electron flow)- and C4 plant)-,r:4,s:0,i:91

  • Bibliography Cntd.(CAM plant)-,r:5,s:0,i:93(Mitochondria)-